Solid Axle Suspension - How Truck Suspensions Work
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- Опубліковано 8 вер 2024
- What is a solid axle suspension and how does it work? I explore this question, and show you the benefits and down sides of a solid axle suspension.
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Nice vid man. I like it how you make it easy to understand mechanical engineering subjects. I am an engineer and none of my professors in the university explain this stuff better than you. Keep it up.
The energy transfer from one tire to the other can be a plus once you get on uneven surfaces because when one tire goes up it helps push the other tire down and contact the ground maintaining traction. As for clearance there are many types of axles with different clearances but independent suspension has whats called a "Differential Clearance" which basically means it has no set clearance of the differential to the ground, it is always changing with the compression and decompression of the suspension system while the solid axle maintains a more stabile clearance distance and is only affected by the tire size and air pressure. Independent suspension does better at higher speeds than the solid axle but the axle does better at lower speeds than independent.
Yes, many solid axle suspensions use coil springs. Leaf springs are just common on trucks, and I would assume it has to do with cost.
I watched it about a week ago. It was fantastic, what a character. Loved seeing the whole country support him at the funeral.
what
This is a pretty good overview of a solid live axle suspension however I feel the urge to point out some things. A trailing arm suspension does not restrict lateral axle movement unless those arms are triangulated in some way. As you have them drawn there would be ZERO lateral location of the axle which means it would move laterally under the car easily. Trailing arm live axle suspensions either incorporate some form of lateral locating device like a panhard bar or watts link OR are triangulated in some way such that there is a force holding it under the car. A perfect example of a triangulated trailing arm suspension is the 3rd and 4th Generation Mustang triangulated 4 link. This setup has HUGE compromises that make is a horrible choice for handling environment but it works well for drag racing. By contrast the 5th Generation Mustangs have a 3 link + PHB. Remove the PHB and the axle can move freely in the lateral direction (causing a lot of damage!)
I would also argue that the notion of "bumps" causing huge issues in traction is wildly overplayed. The elasticity of the modern tire is not so rigid that one wheel bumps drastically alter the contact patch at the other end of the vehicle. Instead the method of lateral location is primarily to blame. Why? With a PHB configuration, or leaf springs or a triangulated 4 link setup the axle will move laterally under the car during bump travel. Take a 300lb pendulum under a 3500lb car and imagine what the effect of the axle moving laterally under the car does to the weight on the rear tires and the contact patch. If you could remove that lateral displacement the majority of the issues with mid corner bumps disappears and becomes a minor problem.
Also, a PHB does not keep an axle from moving laterally under the car. In fact if you plot the path a PHB inscribes it will move the axle in an arc. That's a mighty big pendulum to be swinging under a car in bumps. The effect of this arc is amplified with soft OEM bushings. The less deflection the bushing has the less the axle moves laterally while cornering. When you hear reviews about the 2005-14 Mustangs having problems with mid corner bumps, this is 95% the problem. Replacing the PHB with a watts link removes almost all of this problem and the car is instantly more stable over bumps.
Finally, an independent rear suspension isn't as independent as you imply. I'm sure you go into more depth with the swaybar video but in an independent suspension, a swaybar ties the wheels/tires together in a way similar to that of a live axle only it is not entirely rigid. That depends entirely on the spring rate of the swaybar.
There was a reason I included the panhard rod in the video (lateral deflection). Seems like you're having a good time with my videos though. :)
Thank you for confirming that the Panhard bar moves in a arc, therefore slightly slide laterally the whole axle (or body) over a bump. Nice because I was wondering that looking at my suspension the other day.
IFS is good for off-road on trails where you need traction mostly, and maybe even going faster/ However, when it comes to crawling over huge rocks, solid axles front and back are the way to go for much better articulation, and less danger of tipping over since solid axles are the best at keeping all 4 wheels on the ground in rock crawling. You can use independent suspension for light to moderate rock crawling, but it can't be over rocks that require a lot of articulation.
Dcc357, You arTICKLEated that well! 😎
Body roll will depend more on the suspension components (springs and roll bars) more than the set-up. Soft spring rates will allow either to have a good amount of roll, firmer spring rates will reduce roll.
Hahaha I had a party on the 24th of may to celebrate the 1 year countdown of Fast and Furious 6. Love those movies, they have high entertainment value. But I really do want to watch the Senna film, I'll get to it sometime.
I'm yet to watch that. I tried once but I couldn't get the subtitles to work. I have netflix now though so I'm going to watch it eventually, what an incredible driver.
Solid axles:
Have constant ground clearance regardless of vehicle loading, or vehicle stance.
Do not not load momentum forward under deceleration.
Are virtually maintenance free.
Have fewer parts.
Usually allow for more articulation.
Are better for towing.
Easier to repair.
Cheaper to buy.
Better for drifting.
Often allow for lower COG.
Generally feel more predictable in slow, off camber situations encountered in off road use.
utah wanderlust700
How do they allow for a lower COG? :-/
max mustermann because it's alot of weight at the lowest part of a vehicle.
I would like to know how it would be better for drifting.
Thanks for this video, I've been trying to find more information on panhard rods and you always manage to explain everything well.
you are the god of automobile, without you engineers cant pass their exams of automobile .....thanks dude :)
Nicely explained. You must be busy man after 9 years of this video. Would like to see side by side comparison of suspension specially for 4x4
really appreciate that you are including footage of an actual car suspension. makes it a lot easier for me to understand. thanks again and keep up the awesome videos
One benefit is in an off-road situation is that when one tire goes up it pushes the other down, which helps keep traction to both tires.
That isn't a benefit as independent suspension forces all tires to ground using spring pressure like on Tatra trucks.
Another advantage of a solid axle suspension is that under the assumption that the differential is the point of minimum ground clearance, is that the ground clearance does not reduce during compression.
Unless you know of one, every independent suspension will reduce ground clearance as they compress. Meaning, the differential gets closer to the ground as the suspension compresses, assuming the differential is the point of minimum ground clearance.
Clearance is gonna reduce somewhat in compression, due to sidewall flex in the tires. Remember, tires are effectively "suspension," too. (Think big balloon tires on bush planes.)
You forgot to explain how a Watts linkage works as an alternative to the Panhard rod, and also another of the pros of this kind of suspension is that it keeps camber and track width constant when the vehicle's body rolls in high speed turns.
By the way, an interesting and very rare variation of solid axle is De Dion axle.
Thought I'd prep with this before watching your new Bronco video lol
that is one annoying knee....
great video mate
For heavy duty trucks and extreme off road you want solid axles. For sports cars and family cars your want independent suspension.
Tatra uses independent suspension for each of their tires and they're considered the best heavy duty and off road trucks around by many.
If you are trying to save money. Independant suspensions can be built to handle heavy duty applications, but it costs more, and companies trying to cut costs with people who aren't concerned with handling will use solid axles as a result. Same with rock crawling. If you asked someone to build a vehicle from the ground up for rock crawling as a prototype vehicle with no price maximum, and the only goal being "to win" it would have an independent suspension.
Great video. Comments/questions/myths...
1) Leaf springs allow you to add/remove springs.
2) I'm having a difficult time imagining an independent suspension being more comfortable than a straight axle, unless the tire is going up several feet. But for the typical pot hold or speed bump?
3) Independent front suspension seemed to gain popularity around front wheel drive and going lightweight.
Sorry, contradicted myself there. I'm very tired but also very high and very much enjoying your videos.
One thing to note, almost no car on the market is true independent suspension due to the use of sway bars. Almost all cars on the market link one a arm to the other via the sway bar, hitting a bump with one tire will impact the other with a shutter shake .
Ok thank you for your responses. Just thought cornering may be affected by suspension set ups too. I know they typically do this evaluation in new cars where the measure the Gs in the turns. Same tires gives different results with different cars. But I guess it has more to do with the rubber in the tire (coefficients of friction), weight of the car (normal force), weight distribution (on each tire), and front wheel drive rear wheel drive (oversteer vs under steer).
When you say grip, I believe you mean sustained cornering force (i,e. the ability to change direction(, for which the dominating factors are weight and traction (which itself is a combination of weight/down-force and the dynamics of the tyre).
all trailing arm/ 4 link / 3 link setups need a panhard rod, or to performance on road situation, a watts link, unless it's a triangulated setup. it ain't optional or just on some bigger trucks
Yes, tires are the dominating factor in grip - they are after all, the only point of contact between the car and the road.
Clearance is not always a issue.
Some vehicles (mainly FWD minivans, I think) have a solid rear axle with no differential...
Because an independent suspension cuts the link between the two sides. So if one side needs to move up, and the other remain flat, the single tire will go up (to an extent) without a need for the entire vehicle to lean.
Well, I suppose it really doesn't make a large difference in comparison to an independent rear suspension. But the drive shafts cannot be angled at all, where they can with IRS. So in theory this could mean greater clearance.
Apologies to nit-pick but weight (in combination with down-force i.e the total force acting downwards on the tyre) is equally important to the grip level. Obviously the tyre durability will be an important factor in the real world.
I'm talking about grip, or traction, and not the sustainable cornering/braking/accelerating forces, which are 2 totally different things, where the dominating factor is obviously weight.
When it comes down to it, in theory an independent setup is better off road. The issue is independent is really only better in desert areas (high speed off road conditions hence hummers suspension) and that's about it. Even without factoring in durability, you still have to realize that a solid axle offers more traction at low speeds period. Because the forces on one side force the other side into having traction too(go over a rock and it not only raises one side it pushes the other down harder)
The way I understood it is that leaf springs are stronger and able to take more weight than coils but less comfortable, my pick up had coil fronts and leaf rears and could carry anything without the back end dropping noticeably. Was definitely worse to drive in regard to traction both on and off road than coil front/rear though
I feel as if he is under informed, there are leaf springs and trailing arms, Independant suspension tries to keep the wheel on the ground the whole time, he doesn't talk about the leaf spring mounts, and that they can be raised lowered, and have a lot of different weight, and emergency springs (overload springs) stop the shocks from bottoming out
Another downside of the solid axle (or "live axle" as the Brits would call it with this particular type) is the reaction to the rotating masses inside the differential when the axle pivots. Anyone who's ever held a playing portable CD-player and moved it around, especially in the same plane as the disc was spinning, will have felt a similar reaction.
A De Dion axle doesn't have this downside as it used a solid axle to suspend the wheels but the diff is separate from it and bolted the car. Another benefit is it lowers the unsprung mass.
Lenny, I thiMk we should have at least a DOZEN names for it myself! It keeps us on our toes!!! 😜
Can you help me out with a problem? So I own a Suzuki Jimny and after lifting it 2" panhard bars moved axles to the right. I'll make adjustable panhard bars but I'm wondering should I also adjust the angle of panhard (via relocation bracket) in relation to the axle? Would a parallel panhard be better for vehicle handling? Tnx.
What a bizarrely timed question, I'll have a video next week on trailing arm bushings. I bought a special tool for my car for installing them, but you'll likely need a hydraulic press.
You are partly right but the independent is designed for comfort as one tire hits a bump it takes the impact rather than an axle wich tranfers the impact through the vehicle.
not from what ive experienced. maybe some vehicles are bouncy with leaf springs, but the ones i've been in have been very smooth even on fairly rocky dirt roads. suppose it depends on the vehicle and what its designed for...
May you kindly do a video on watts linkage and its advantages
Thanks ...I m big fan of your videos & explanation technique.
Can you please take lecture on "Actuators- Types & working principle of each"
Thank you.
I like your early style more. It is more straight forward and detail-oriented to raw information, instead of daily talk style like your recent videos
hey! can u make a video which explains trailing arm suspention in detail
A Live or solid Axel will actually be better for clearance on offroad situations, as it will rise up the whole body when hitting a rock or pothole
Trailing arms with coil springs. My next video will actually be a little discussion on this topic.
Please make a video regarding 4-link suspension please. :) I'm trying to make a 4x4 project in my backyard.
+eaxebxecxedx i was just about to ask that
What you forgot to mention is that the clearance stays constant with the solid axle, whereas with the independent suspension it changes as the body of the car goes up and down. It is very important for off-road vehicles, and in my opinion is the most important advantage of the solid axle.
just pointing out over here, but many other cars/crossovers and stuff are Awd and yes it is very beneficial. even if you have the part time 4x4 as seen on many suvs and trucks. either one when based on the FR layout with extra driveshaft, it provides the torque steer and the digging into snow instead of wheels pushing it and any benefits of Fwd, while providing the Rwd pushing factor and the durability, balance and longevity that i'm sorry, Fwd just doesen't have. not that special, but helpful.
Actualy axles have more traction than independent BECAUSE the axle has a farther travel length and is concidered "unlimited" in travel and maintains clearance, when one tire goes up the other goes down thus you maintain a perfect traction while independent travels with the frame or body of the vehicle when one tire goes up the other goes up and you lose traction.
You talked about camber in the independent rear suspension video. In IRS, the upper control arm is shorter than the lower control arm to account for body roll.
How is the performance of solid axles when taking turns (i.e. body roll) relative to IRS?
could you explain the de Dion axle used in the caterham 620r?
This guy is Awsome! He would B a good Auto Tech
You forgot to mention that with a solid axle you can get much better atticulation for extreme off road conditions. For example the ram power wagon has more then twice the wheel travel than the ford raptor, which makes to powerwagon much more suitible for rock crawling and rugged terrains. Its is also far more durable. The ford raptor on the other hand is more suited to high speed offroading and desert terrain due to its ifs. My take on it is that the raptor is a purpose built high speed offroad truck thats primary purpose is being fun and is more of a toy. The power wagon is a great rock crawler and general offroad truck and can also serve as a work truck. Personally I would take the powerwagon
Yes, though if you have the "nicest" suspension in the world, but have plastic tires, you'll never go around a corner at the same speeds as something that has no suspension and sticky tires. (Yes, of course if there are bumps the second car will have a tough time, it's just important to know why such high lateral g's are capable in ideal conditions).
With a panhard rod though, on bump, the axle does have lateral movement, since the panhard rod moves in an arc.
Very good video
I love your video's! They've helped me so much, thank you!!
Very welcome, thanks for watching!
Why do you say it is special in the first place? Just curious what your reasoning is. Audi's is kinda unique in a sense that they try to do everything mechanically, without the aid of electronics - at least that's what they used to do, could have changed. And as stated below, almost all Subarus do come standard with AWD, but as far as why it's special, it's just AWD. AWD has numerous advantages, so perhaps that is why it is "special."
Can you explain the relationship between the angle of the track bar (panhard bar) and the drag links , if the angle is too great how does it cause bump steer ? And how does “Death Wobble “ become a problem once you lift a vehicle with solid axles
I was waiting for this for a long time! Thanks, now I understand alot more how my car reacts to the roads & imprefections! A+ as always!
?? I'm not sure what you're referring to. A solid axle is not an independent suspension setup.
Plz explain abt...multi link off roaders suspensions ...tuning procedures etc...
Hello I have a question
I have a 5 tons Isuzu npr 2wd small truck and I want to transform to 4wd but I don't know which is the right axle for this truck can you help with this
Thanks for the video. one question - which would perform better on twisty unbanked roads, solid axle or double wishbone/multilink?
Depends....R U using a flux capacitor, or no??? 🤔
Humvees and quad bikes are examples of highly capable off road vehicles with independent suspensions.
How is it worse for traction and handling in an off road scenario? First thing I do with my trucks is cut out the independent suspension and put in solid if it doesn't already have it. That being said I'm talking about trucks exclusively for off road
yes, might be for cost but with the advent of luxury trucks like rams laramie,fords lariat/platinum and others, many trucks are very expensive and focus on comfort so the cost wouldnt matter on those. maybe on the lower and base models. but many of these trucks still have leafs. the ride must be nice on coil springs..wouldn't hurt on a truck not worked much too considering myself and enough others would just buy a truck cause they like them not cause they need them...
Greetings for 2019!
Greetings from 2020
Suspension or drive train? The suspension and the engine aren't directly linked like the engine and drive train (transmission, diffs, axles).
Greetings for 2020!
will you please explain trailing and semi-trailing arm......
Can you explain the Ford twin I beam suspension I understand allitle how it works and I think it would be great for more people to understand and for me to learn more about it
this can have a coil spring setup as well, right? for their 2009 fourth generation redesign, dodge ram 1500 switched to coil springs from leafs. would not seem to be ideal for a full size truck but apparently it works good and theres not much change in truck capability...that must be the suspension setup...
You should do a video about what happens when you torch your springs
Maybe I got it wrong then. But I always thought that Dodge Rams were criticized for having the most power engine and a chassis that wasn't "tuned" (or balance) for it. I've always wondered what that meant.
Hi Jason, great video.. One thing that bugs me is, how does differential work with individual suspension? Hope you can make a video about it..
Same idea but there are CV axles. So the same idea as the drive shaft applying power to the rear differential while it moves ... Think of two more drive shafts like that going to either side called CV axles/joints. They can twist while moving up and down.
Can you put a coil-over system in a solid axle suspension?The "block view" type in particular.
This guys has been at this for a while, helo 2020:)
I have a question for you.
I was thinking about straight axle suspension, and I was wondering how sway bars would affect those.
I just watched your sway bars explained video. I know it's the same concept, I just don't see how the sway bars would help the straight axle.
Jonathan Brown Similar concept, this may help: i1212.photobucket.com/albums/cc443/BadBirdMatt/LiveAxleSway.jpg
So I guess the amount of grip would be the same regardless of the suspension? Reason I ask is because I drive a Mazda miata and mazda 3. Both are good cars, but have very different amounts of grip (ie when I take the turns). Does this have more to do with the tires than suspension?
Would love to see a video on portal axles
I wonder if this is why the 1st gen Honda Passport’s handling is really heavy- not only is it a 4x4, but despite it having front double wishbone suspension, it has a leaf spring solid axle rear end.
I like that to show the solid axle, you went to a junk yard, where all solid axels belong. The only reason IMHO to run a solid axle is to be cheap, and produce a cheap vehicle. I agree that independant suspensions are more likely to break, but as an engineer, that isn't a limitation, that is just that to achieve comparable strength and reliability would be more expensive. Monster Trucks, and Baha pro trucks will use independent suspension because you get more grip, and more control as an engineer. The only reason solid axles exist is because they are cheaper to produce. If an independent suspension with comparable strength was cheaper, that would be the only suspension you would see on a truck. With drag cars, I feel like its more an issue of weight. A car that only has to go in a straight line but has tons of power is going to need strong axels, and a differential that can take a lot of torque, and having a solid axel means it requires much less material and thus weight to achieve this goal. A normal race car doesn't have the same impact typically put onto the differentials and axles since it is important to maintain as much speed as possible, and try and drive as smoothly as possible. Thats why makers like Lamborghini have notoriously weak clutches, transmissions, and differentials. They aren't really about launching like a muscle car, or doing burnouts, whereas even if you drive hard on a track, there is power being transitioned, but it isn't as abrupt as a launch.
Whoa dude, good job at making these videos. Thanks!
Giddy up.......d00d!
@@mr.blackhawk142 Whoa.
i want to ask you a question ?
which better the torsion beam or the multi link ( dual link ) suspension for sport driving
Hey I am actually working on a trike project could you suggest which suspension would be best suited and what are pros and cons of not using suspension in a tricycle
Could you da a video about the integral axle, witch is used in the BMW 5 series ?
That's not what happens out on the trail. IFS has extremely limited droop and compression capability. This means if one side goes up onto a tall rock the whole front of the vehicle will be lifted up and the other tire will leave the ground losing all traction. A solid axle on the other hand will articulate and when one side goes up, the other side is forced down into contact with the ground. IFS is great for a smoother ride on wash board trails, but a solid axle is superior in extreme conditions
nice video ! great explanation!
Good
Bro
maybe i missed it but what is the lightest type of suspension?
Also, is there a particular type of suspension used for retractable wheels?
alek syd The lightest suspension is the one with the lightest materials (or the smallest). I wouldn't base it on "type." They're all fairly unique.
How is the clearance differential issue exclusive to solid axle suspension?
Can you please suggest a software for suspension analysis?????
Nice job thanks!
Great video, thanks for the info!
what type of solid axle does the mustang use? and would ford decide to implement it?
What if I'm a Vin Diesel and Paul Walker fan?
Can you explain why Audi's and Subaru's AWD system is special? Or not special?
Are solid axils limited to closed differentials?
hi there. i changed the bushings on the trailing control arms of my g class w461. what i wante to no is there a special way to install them back ?